/Engine/Plugins/Animation/ControlRig/Source/ControlRig/Public/Rigs/RigHierarchy.h
Returns true if the hierarchy controller is currently available The controller may not be available during certain events. If the controller is not available thenGetController()will return nullptr.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintPure, Category=URigHierarchy) bool IsControllerAvailable() const